Perforating apparatus



Oct. 5, 1965 M. P. LEBOURG PERFORMING APPARATUS 2 Sheets-Sheet l FiledNOV. l, 1962 INVENTOR.

Wwf/JM Oct. 5, 1965 M. P. LEBQURG PERFORATING APPARATUS 2 Sheets-Sheet 2Filed Nov. l, 1962 Maar/ce scu/y BMM/1 M4@ United States Patent33,2%,828 Patented @on Ei, i965 3,209,828 PERFORATlNG APPARATUS MauriceP. Lebourg, Houston, Tex., assignor to Schlumberger Well SurveyingCorporation, Houston, Tex., a corporation of Texas Filed Nov. 1, 1962,Ser. No. 234,783 3 Claims. (Cl. 16d-55.1)

This invention relates to apparatus useful for independent completion ofone or more co-extensively extending tubing strings which are disposedin a common oil well borehole. In particular, this invention relates tonew and improved apparatus for locating adjacent strings of tubing froma given large diameter string of tubing in a well bore with a greaterdegree of accuracy, and perforating the given string of tubing in aselected direction of orientation.

The technique of multiple completion involves the positioning ofco-extending strings of tubing in a common borehole, cementing thestrings in place in the borehole, and using orienting perforatingapparatus to selectively perforate one or more of the tubing strings.The orientking perforating apparatus generally includes a pipe or tubinglocating apparatus, an indexing device and a directional perforatingdevice which are lowered into one string of tubing to a depth whereperforations are desired. The adjacent tubing strings are located byindexing the pipe locating apparatus and the directional perforator isthen oriented relative to the co-extending strings of tubing so as tolire in a selected direction, typically away from the other strings oftubing. Each string of tubing is completed in this manner. Heretofore,multiple completion of wells has been limited to tubing strings having asmall diameter, say 2 or 21/2 inches, and oriented perforator apparatusis correspondingly sized for operation in this small diameter tubing.Howevera where the string of pipe has a substantially larger diameter,say 41/2 inches, the small diameter orienting perforating apparatus isgenerally inadequate for several reasons. First of all, the apparatus,when centered in the large diameter casing, has a large standoffdistance thereby reducing the performance of the perforating apparatus.The pipe or tubing locating apparatus, which generally is aradioactivity device, has a tremendously decreased sensitivity becauseof the large standoff spacing and it is, in fact, extremely dilicult todetect the presence of adjacent strings of tubing because of this largestandoff.

An obvious solution to this problem is, of course, to increase thediameter of the orienting perforating apparatus to a size comparable tothe large diameter casing. But, such a solution requires duplicate toolsin a range of sizes, and larger diameter tools correspondingly haveincreased weight and raise difficulties in orienting the apparatussuccessfully.

Accordingly, the present invention is to provide new and improved smalldiameter orienting perforating apparatus for use in large diameterstrings of tubing.

Another object of the present invention is to provide new and improvedsmall diameter orienting perforating apparatus for use in a range ofdifferent diameter tubing strings.

A still further object of the present invention is to provide new andimproved small diameter orienting perforating apparatus providingincreased accuracy of orientation and perforating performance in largediameter well bores.

The present invention includes an assembly of small diameter perforatingapparatus, radioactivity pipe locating apparatus and indexing means withinterconnecting positioning means arranged to position the perforatingapparatus and locating apparatus proximate to the wall of the tubingstring in which it is positioned.

The novel features of the present invention are set forth withparticularity in the appended claims. The .present invention, both as toits organization and manner of operation together with further objectsand advantages thereof, may best be understood by way of illustrationand example of certain embodiments when taken in conjunction with theaccompanying drawings in which:

FIG. l is a view illustrating apparatus of the present inventiondisposed in a well bore;

FIG. 2 is a view in cross-section taken along line 2-2 of FIG. 1;

FlG. 3 is a view in cross-section taken along line 3 3 0f FIG. l;

FG. 4 is a View in cross-section illustrating pipe strings in a wellbore and apparatus in one pipe string; and

FlG. 5 is a partial plan view of indexing means.

Referring now to FIG. 4, a large diameter string of pipe lid and smalldiameter string of pipe ltla are shown traversing the earth formationslil and cemented in place by `a column of cement l2. Shown positioned inthe string of pipe lll is orienting perforating apparatus 13 accordingto the present invention. The assembled apparatus 13 is adapted to belowered into the pipe string l@ by means of an electric armored cable ld(FIG. l) spooled from a winch (not shown) at the earths surface in aconventional manner. The pipe string ill is typically filled with a wellcontrol fluid such as mud.

As shown in FIG. l, the apparatus lf3 includes a conventional casingcollar locator l5 connected to an indexing device lo, a directionalradioactivity pipe locating means i7 and a directional perforator i3.The elements 1648 are sized to pass through a small diameter tubingwhich is the range of tuhings in 2 and 21/2 inch sizes.

The indexing device la generally includes a tubular mandrel 19 and atubular cage 2i) slidably received thereon. Cage 2t) is sized to bepassed through a small diameter tubing but has attached, peripherallyspaced, bow springs 2l sized for frictional engagement with the pipeill. Mandrel i9 has a slot system 22 in its outer surface while cage 2lihas a follower 23 for the slot system. Follower 23 may, for example, bea spring clip ring with an end portion extending through the cage Ztlinto register with the slot, the end portion being resiliently movableinwardly and outwardly relative to the cage 2li.

As shown in partial view in PEG. 5, the slot system 2l includeslongitudinal slots 2d and transverse connecting slots 25. rl`he endportion of the spring clip ring is shown at 2o. The slots 2li and 2Shave inclined portions 27 which extend from a bottom surface of a slotto a shoulder 28 to a point below the outer surface of the mandrel i9.In operation, if the end portion 2d is in a longitudinal slot, it willbe guided up an inclined surface 27 and over a shoulder 23 when themandrel is moved relative to the cage in an upward direction. Movementthen in a downward ldirection will bring the end portion 26 intoengagement with a shoulder 2%, and end portion 2d will be guided into atransverse slot 25 to rotate the mandrel until the end portion 26 passesover a shoulder 28 of the longitudinal slot.

The directional radioactivity pipe locating means i7 includes a focussedsource of radioactivity 3i) and spaced therefrom a suitable distance afocussed detector of radioactivity 31. These devices may, for example,be a gamma radiation source such as Cs 137 and a Geiger-Mueller tube.These devices cooperate in a well-known manner so that radioactivityinduced by the source is detected in a directional manner by thedetector tube. The directional sensitivity is shown by the arrow 34 inFIGS. 2, 3. For optimized sensitivity, the source and detector should belocated proximate to the wall of the tubing in which they arepositioned.

The perforating apparatus 1S may, for example, be of the typeillustrated in my Patent No. 3,048,102 where the shaped charges are alloriented to iire in a single direction as illustrated by the arrow 33 inFIGS. 2 and 3.

interconnecting the indexing device 16 and the radioactivity pipeorienting device i7 is a coupling member 3d having a centered end 37, aneccentered end 38, and an intermediate centered portion 39. The centeredend 37 has a first opening 40 about a first axis 41, the axis dit beingcoextensive with the central axis of the pipe l@ when the apparatus iscentered in the pipe l0. Opening 40 extends into the intermediateportion 39, the opening 40 having a threaded portion adapted to receivea threaded end of the indexing device 16. The intermediate portion 39has an outer cylindrical surface which is concentrically arrangedrelative to the tirst opening liti and sized to a diameter just slightlyless than the diameter of the large diameter casing, say on the order of1/2 inch. In the eccentered end 38 of the coupling member is a secondopening 43 about a second axis i4 which is offset and parallel to axis4l. Opening 43 extends into the intermediate portion 39 and opens to thefirst opening 40. The second opening 43 also has a threaded portionadapted to receive a threaded end of the pipe locating apparatus 17. Thecommon plane defined by the first and second axes 41, 44 is here denedas a plane or orientation and identified by the numeral 45. Thedirectional sensitivity 34 of the pipe locating means ll? and thedirection of tiring 33 of the perforating apparatus i8 lie in plane 45but face in opposite directions.

Another coupling member 36a interconnects the pipe locating apparatus 17and a centralizer sub 47, the coupling member 36a being reversed inposition relative to the coupling member 36 so that the axis of theopening in the eccentered end 38a. coincides with the axis 44 ofcoupling 36 while the axis of the opening in the centered end 37coincides with the central axis of the centralizer sub 47 and thecentral axis 41 of the pipe 10. The centralizer sub 47 has the usual bowsprings 48 thereon for centering the apparatus in the pipe il() and isconstructed so that a mandrel is rotatable relative to the outer tubularcage which has the springs 58.

From the foregoing, it will be appreciated that coupling members 36, 36aare identical but reversed in position so that pipe locating device 17is eccentered relative to the central axis 4i of the pipe 310, the pipelocating device, however, being within an imaginary cylindrical envelopedefined by the cylindrical intermediate portions 39, 39a of the couplingmembers. The intermediate portions 39, 39a protect the device 17 fromdamage in the pipe while insuring the close positioning of the device 17to the wall of the pipe.

At the lower end of the centralizer sub 47, another pair of couplingmembers 36h, 36C are reversely positioned and connected to the ends ofthe perforator 18 so that the axis 44a of the perforator is eccenteredwith respect to the central axis of the pipe i0, the perforator device,however, being within an imaginary cylindrical envelope defined by theintermediate portions 39h, 3% of the coupling members.

From the foregoing description it will be appreciated that the apparatusdisclosed resembles a crankshaft wherey the apparatus is centered in apipe but has components thereof displaced radially from the central axisof the apparatus to place such components proximate to the wall of thepipe.

In operation, the apparatus is lowered in the pipe to the level to beperforated. Bow springs 2l and d8 centralize the apparatus in thepipestring. The cable 14';- is then lifted up a short distance to bringthe index pin in the lower end of the slot system and lowered tooriginal position, thus indexing tool to adjacent slot. Radioactivitymeasurements are made and the cable 14 reciprocated thereby rotating theradioactivity apparatus through the distance between adjacent slots ofthe slot system. Radioactivity measurements are taken for each rotativeposition througha 360 arc. From the radioactivity measurements, thelocation of the adjacent pipestring, or for that matter, any locatableobject is determined and the preforator oriented as desired,

While a particular embodiment of the present invention has been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

l. Perforator orienting apparatus for large diameter pipe stringscomprising: radioactive pipe-locating means having a given radialdirection of sensitivity; an indexing device including wall-engagingmeans to centraiize the apparatus in such pipe string, and a memberrotatable about a central axis of the apparatus relative to saidwall-engaging means; perforator means having a given radial direction offire; means coupling said radioactivity locating means, said rotatablemember and said perforator means in fixed relation to one another, saidcoupling means including an interconnecting member above and coupled tosaid radioactivity locating means where said radioactivity locatingmeans has a cross-sectional size substantially less than thecross-section of such pipe string, said interconnecting member having anaxially offset portion arranged to eccenter said radioactivity locatingmeans relative to the central axis of said apparatus and position saidradioactivity locating means proximate to the wall of such pipestring.

2. Perforator orienting apparatus for large diameter pipestringscomprising: an indexing device including wallengaging means for contactwith the wall of a pipestring and a member rotatably mounted about acentral axis relative to said wall-engaging means, radioactive pipelocating means having a given radial direction of sensitivity;perforating means having a given radial direction of re; said pipelocating means and said perforating means having a cross-section sizedfor passage through a small-diameter tubing string; and means couplingsaid rotatable member, said pipe locating means and said perforatingmeans in ixed relation to one another, said coupling means including apair of interconnecting members having axially olfset connectingportions for each of said pipe locating means and said perforating meansarranged to displace said pipe locating means and said perforating meansrelative to said central axis, said pipe locating means and perforatingmeans being arranged with their respective radial direction ofsensitivity and radial direction of lire disposed in oppositedirections.

3. As a subcombination, apparatus for use in a pipestring in a well borehaving a central axis comprising: radioactivity-sensing means having agiven radial direction of sensitivity; means for rotating saidradioactivity-sensing means about said central axis; wall-engaging meansfor centralizing said rotating means along said central axis Within thepipestring; and means dependently coupling said radioactivity-sensingmeans to said rotating means for eccentering said radioactivity-sensingmeans relative to said central axis; said coupling means including anaxially offset portion arranged to eccentrically displace said radio-factivity-sensing means in said radial direction and into proximity withsaid pipestring.

References Cited by the Examiner UNITED STATES PATENTS Abendroth 166-555XR Dunn 175-57 Popham 166--35 True 166--55 Diebold IGZ- 21.8 True 166-55XR Kenneday et al 166-55.1

CHARLES E. OCONNELL, Primary Examiner.

3. AS A SUBCOMBINATION APPARATUS FOR USE IN A PIPESTRING IN A WELL BOREHAVING A CENTRAL AXIS COMPRISING: RADIOACTIVITY-SENSING MEANS HAVING AGIVEN RADIAL DIRECTION OF SENSITIVITY; MEANS FOR ROTATING SAIDRADIOACTIVITY-SENSING MEANS ABOUT SAID CENTRAL AXIS; WALL-ENGAGING MEANSFOR CENTRALIZING SAID ROTATING MEANS ALONG SAID CENTRAL AXIS WITHIN THEPIPESTRING; AND MEANS DEPENDENTLY COUPLING SAID RADIOACTIVITY-SENSINGMEANS TO SAID ROTATING MEANS FOR ECCENTERING SAID RADIOACTIVITY-SENSINGMEANS RELATIVE TO SAID CENTRAL AXIS; SAID COUPLING MEANS INCLUDING ANAXIALLY OFFSET PORTION ARRANGED TO ECCENTRICALLY DISPLACE SAID RADIO-